People collect a lot of different things, e.g. stamps, coins, sea-shells and of course more abstract things. Why shouldn't there be some collecting strange things like lichens?
Many lichens - especially crustose ones - can not be identified in the field. You have to take a specimen home to investigate more closely, e.g. make sections, measure spores or test out chemical properties of the lichen.
It is useful to have reference material from different localities to study the variability of the species or the influence of the habitat. Lichens are influenced by several factors like the substrate, the habitat and also by pollution. There are lichens indicating nitrate and other substances, so it could even be interesting to compare lichens collected nowadays and the ones you took with you twenty years ago.
Specimens are collected in the scientific herbaria of universities and museums as a proof that certain species have been found in certain places. Scientists who want to study e.g. a certain lichen genus or family can borrow the lichens from different collections in different countries and compare them.
Whenever you collect a specimen you should however bear in mind that lichens many lichens belong to the endangered species. You should be very careful not to destroy the lichens in its site and collect only a small piece of the thallus, not more than you need for the identification.
© 2002,2003 by Richard Burghause, Germany. All rights reserved.